Method for up-scaling an input image and an up-scaling system

Abstract

The invention relates to techniques of up-scaling an input image represented by an input video signal in an image up-scaling system, especially to a method and an image up-scaling system for up-scaling an input image represented by an input video signal, the method comprising steps of receiving and processing the input video signal in an up-scaling device ( 21, 23 ), providing a linear up-scaled video signal generated by the up-scaling device ( 21, 23 ) to a signal combining device ( 24 ), receiving and processing the input video signal in a harmonics generation device ( 22, 25, 26, . . . , 30 ), generating an up-scaled output image represented by an up-scaled output video signal by combing the up-scaled video signal with a higher harmonics video output signal provided by the harmonics generation device ( 22, 25, 26, . . . , 30 ) in the signal combining device ( 24 ), and providing the up-scaled output video signal to an output of the combining device ( 24 ).

1. A method for up-scaling an input image represented by an input video signal in an image up-scaling system, the method comprising steps of:
 receiving and processing the input video signal in an up-scaling device ( 21 ,  23 ), wherein the step of receiving and processing the input video signal in the up-scaling device ( 21 ,  23 ) comprises steps of:
 generating a first up-scaled video signal from the input video signal by up-scaling the input video signal by a rational factor of L/M, wherein L is an interpolation factor used for an interpolation of the input video signal in an interpolation element in the up-scaling device ( 21 ,  23 ), and M is a decimation factor used for a decimation in a decimation element in the up-scaling device ( 21 ,  23 ), and 
 providing the first up-scaled video signal to a signal combining device ( 24 ), 
 
 receiving and processing the input video signal in a harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ), wherein the step of receiving and processing the input video signal in the harmonics generating device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises steps of:
 generating from the input video signal a higher harmonics video output signal representing higher harmonics of the input video signal in a frequency domain, the generating of the higher harmonics video output signal comprising steps of up-scaling the input video signal by a factor of k×(L/M) (k>1) to form a second up-scaled video signal, generating a higher harmonics video signal from the second up-scaled video signal, and decimating the higher harmonics video signal by a decimating factor of k, and 
 providing the higher harmonics video output signal to the signal combining device ( 24 ), 
 
 in the signal combining device ( 24 ), generating an up-scaled output image represented by an up-scaled output video signal by combing the first up-scaled video signal with the higher harmonics video output signal, and 
 providing the up-scaled output video signal to an output of the combining device ( 24 ). 
 
     
     
       2. Method according to  claim 1 , wherein the step of generating the higher harmonics video output signal comprises a step of limiting the higher harmonics video signal in the frequency domain to frequency below a Nyquist frequency limit, wherein the step of limiting is performed by a low-pass filter element ( 28 ). 
     
     
       3. Method according to  claim 1 , wherein the step of generating the higher harmonics video output signal comprises a step of deriving input video signal information from the input video signal by processing the input video signal. 
     
     
       4. Method according to  claim 1 , wherein the step of up-scaling the input video signal by the factor of k×(L/M) (k>1) is performed in a diamond scaler element ( 26 ). 
     
     
       5. Method according to  claim 1 , wherein the step of decimating the higher harmonics video signal by the decimating factor of k is performed in a decimation element ( 29 ). 
     
     
       6. Method according to  claim 1 , wherein the step of generating the higher harmonics video output signal comprises a step of amplifying in an amplifier element ( 30 ). 
     
     
       7. An image up-scaling system for up-scaling an input image represented by an input video signal, the system comprising:
 an up-scaling device ( 21 ,  23 ), configured to:
 receive and process the input video signal, and 
 generate a first up-scaled video signal from the input video signal, 
 
 a harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ), configured to:
 receive and process the input signal, and 
 generate from the input video signal a higher harmonics video output signal representing higher harmonics of the input video signal in a frequency domain, the generating of the higher harmonics video output signal comprising steps of up-scaling the input video signal by a factor of k×(L/M) (k>1) to form a second up-scaled video signal, generating a higher harmonics video signal from the second up-scaled video signal, and decimating the higher harmonics video signal by a decimating factor of k, and 
 
 a signal combining device ( 24 ), configured to:
 receive the second up-scaled video signal and the higher harmonics video output signal, 
 generate an up-scaled output image represented by an up-scaled output video signal by combining the first up-scaled video signal with the higher harmonics video output signal, and 
 provide the up-scaled output video signal to an output of the combining device ( 24 ). 
 
 
     
     
       8. System according to  claim 7 , wherein the harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises a low-pass filter element ( 28 ) configured to limit the higher harmonics video signal in the frequency domain to frequency below a Nyquist frequency limit. 
     
     
       9. System according to  claim 7 , wherein the harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises a high-pass filter element ( 25 ) configured to derive input video signal information from the input video signal by processing the input video signal. 
     
     
       10. System according to  claim 7 , wherein the harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises a diamond scaler element ( 26 ) configured to up-scale the input video signal by the factor of k×(L/M) (k>1). 
     
     
       11. System according to  claim 7 , wherein the harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises a decimation element ( 29 ) configured to decimate the higher harmonics video signal by the decimating factor of k to the higher harmonics video output signal. 
     
     
       12. System according to  claim 7 , wherein the harmonics generation device ( 22 ,  25 ,  26 , . . . ,  30 ) comprises an amplifier element ( 30 ) configured for signal amplification.